VTube-LASER Shallow Bend Measure

Why Shallow Bend Measure?

Shallow bend measurement is challenging for all metrology systems. It doesn't matter if the system is accurate or not.  The problem of intersecting 3-D lines that intersect as a shallow bend is common across all devices.

We added the Shallow Bend measurement process to counter the effect of intersection points sliding too much back and forth along the centerline in shallow bend intersections.

The default shallow bend is 10 degrees (see below).  Before using 10 degrees as your shallow bend threshold, we recommend that you perform tests on very shallow bends with your tube shapes. The goal is to determine at what angle of bend the operator becomes more accurate in finding the intersection than VTube-LASER in your application.  Then use that threshold value for all VTube-LASER projects.  For larger diameter exhaust pipes with shorter straights, customers like to use 10 degrees.  For longer straight tubes (relative to the OD), customers will often choose 5 degrees as the threshold.

Measure Setup

The threshold can be set in Measure Setup in row 2.  

Regarding Advanced DCF Shallow Bend Handling: We recommend that you leave this on so that VTube-LASER will ignore Dual Cylinder Fit warnings when it encounters shallow bends.  In fact, with Advanced DCF handling, it is possible to measure a straight tube as a shallow bend measure.

Shallow Bend Process Use on High Angles

We also found that the same problem exists with very high bend angles.  If you use the recommended Split Bend for high bend angles, then this is not an issue. However, if you don't use Split Bends and are measuring angles that approach 180 degrees, the Shallow Bend process may also activate and ask you to measure the intersection point.